Yeah I had the Panasonic 22mbps class 10 card and I sold it cause I thought it was the card...but even the faster card has that issue. I just gave up on using Ex-Tele ...

Will the new UHS-I cards even work in the GH2?... B and H is selling them now..I don't think Ill need one though, my 32gb San disc extreme pro 45mbps card seems Ok .I only get the card slow error when I use Ex-tele and only @720p60 it seems...so I don't think its the cards fault.

http://www.bhphotovideo.com/c/buy/-Panasonic-UHS/ci/17997/N/4191274759

Any difference in speed between a Sandisk SHDC Extreme 8GB or 16GB? Shouldn't they have the same read/write speeds? I thought I've read there are some differences.

@daihard this was a couple of years ago, for a totally different device (i.e. one with microSD slot). Point was the thing was comfortably over-spec and knocking at the door of the next speed class. Take-home message being that the speed-class number is merely a minimum (and refers to read speed AFAIK).

Couldn't say about the lag, new gear still in the post :o) . SXDC is > 32GB rather than speed per se (officially supported on GH2 AFAICT, but their website is kinda vague), and yes, UHS-I is much faster read speed in supporting devices, but write performance is uncertain (early benchmarks showed relative slowness, the interesting question is whether it has improved)

@dkitsov h2testw is free & gives write speed while writing and average write speed when done, and writes / verifies pseudo-random data to be sure that it's stored and not overwritten as on some false-capacity knock-offs... no graphs or other niceness though.

@madact
To add, micro? aren't you worried about the adaptor and any loose connections/loss in data transfer/etc... basically, why micro? cost?

FWIW I have a Sandisk microSD card at class 4 / 32GB, which has read & write speeds not quite up to, but very close to, the class 6 spec.

Apparently UHS-I does use extra pins in UHS devices - but what with write speed being generally much less than read speed for SD cards, I suspect that the limiting factor here is the flash memory itself, rather than the bus.

Of course, it's write speed, not read speed, that we're all interested in, right? ;o)

@dkitsov

The Sandisk Extreme Video is an UHS-I Card, too.

@dazza

I tested an UHS-I Card (Sandisk extreme pro 45MB/s) in a non UHS compatible reader. It was strange. With little blocks it was as slower as a class 6 card, an with 1MB blocks it runs at 45MB/s.

In the GH2 the UHS-I has the same writing speed as a class 10 transcend card.

I just bought a new Lexar USB3 card reader, which I connect to a USB3 port, that sits on a card that is on a PCI-E bus and then I run an HDtach test (not sure how well it works with SD cards) on two different SD cards I have.
1st - SanDisk Extreme Pro UHS-1 45MB/s 16GB. It returned 45MB/s peak and the same sustained (as expected).
Then I tested My SanDisk Extreme HD video class 10 30MB/s 16Gb. And guess what - 45MB/s peak, 45 MB/s sustained. I am speechless.
PS. @Vitaliy_Kiselev Cannot attach a screenshot, get an "Internal Error could not move file" error

I had two 16 GB Sandisk Extreme Pro UHS I Cards, but they´re on the way back to vendor.
I compared it to my Transcend class 6 card in Photo Raw burst mode and it was only a little faster when writing full buffer to card.

The other thing, I got writing errors (camera freezing) with my GH2 hacked in 720p60 Mode (30Mbit/s) and the Transcend class 6 went fine with the same settings.

No, 45€ (16GB) is too much money. I ordered two Transcend 32GB class 10 for the same money:-)

Mine are 16GB SanDisk Extreme Pro 45MB/sec UHS-1. Got them from B&H in new packaging. Tested them with ATTO Benchmark and they came in just a little bit faster than my Panasonic Class 10 cards - that I got direct from Panasonic.

We may well have some sample contamination here - time to google "fake flash" methinks.

@evanflys no idea what cards you tested there - Make? Model? Real, fake, or suspicious?

@cinegraphy have you verified the capacity?

The program "h2testw" verifies capacity and also reports write speed...

Anyway since it's fast and not too expensive, maybe it's good to keep this in mind, if you want to buy a fast card (of course supposing, at least all cards of this model behave the same)